In May, Gov. Tom Corbett stopped by the $35 million cardboard box plant that Pratt Corrugated Materials opened five months before in Lower Macungie Township.

Three months later, he was back to visit a heavy-duty truck chassis assembly plant that Westport Axle opened in Upper Macungie Township earlier that summer.

To area business leaders, Pratt and Westport, opening in quick succession, symbolize the Lehigh Valley's ability to attract manufacturing companies, which offer highly skilled jobs with wages that can support a community, sustain a family and slow the erosion of the middle class.

"The Lehigh Valley itself has a lot of things going for it. It's in the cross hairs of site selectors around the country," said Jack Pfunder, executive director of the Manufacturer's Resource Center, a nonprofit affiliate of Lehigh University.

Manufacturing accounts for more than 12 percent of Pennsylvania's gross state product, according to the National Association of Manufacturers. Using that as a yardstick, Pennsylvania is the sixth largest manufacturing state in the country.

There are 15,000 manufacturing establishments across the state and more than 1,000 alone in Lehigh and Northampton counties.

Statewide, manufacturing employs 574,000 people, or 10 percent of the total workforce, according to the Governor's Manufacturing Advisory Council, a group Corbett assembled to study what the state's industrial sector needs.

The average annual compensation in manufacturing is $64,913, an amount that is 44 percent higher than non-manufacturing sectors, according to the governor's advisory council report. That figure includes high-tech manufacturing jobs that tend to pay higher.

"For job diversity in the economy, we want to have manufacturing and production as a strong part of the mix," said Don Cunningham, executive director of the Lehigh Valley Economic Development Corp.

Cunningham said the Valley is uniquely positioned to attract manufacturing companies.

He said companies are realizing there are savings to be had by producing a product and distributing it from a central location, Cunningham said. And the Valley is within roughly a day's drive of 65 percent of the East Coast metropolitan area.

"The cost of manufacturing here in eastern Pennsylvania is lower than it is in some of the other mid-Atlantic states that would have proximity to that same market," he said. "It's the reason why we're very appealing for the distribution of product."

Location is one of the reasons that Pratt Corrugated Materials, based in Conyers, Ga., picked the Valley.

Anthony Pratt, chairman and owner of the company, has said Pennsylvania offers a better business climate for manufacturers than other Northeast states, and the Valley itself offers convenient access to the company's customers.

Pratt makes cardboard boxes out of recycled materials and employs about 100 people at its plant on Industrial Park Way in Lower Macungie.

In Westport Axle's case, the Kentucky-based company moved into 516,800 square feet of industrial space owned by Liberty Property Trust in Upper Macungie.

Westport makes chassis for Mack Trucks and its new facility is not far from Mack's assembly plant in Lower Macungie.

Westport Axle has a similar plant in Virginia that makes truck chassis for Volvo AB, the corporate parent of Mack Trucks.

When it opened in June, Westport officials said was employing a workforce of 250, a number the company said could eventually double to 500.

At the time, the company said average production-line wages would be between $15 and $16 an hour and that workers would receive benefits.

That's higher than area warehouse jobs, which classified ads show pay between $9 and $13 an hour.

While some Westport workers commute from Lancaster, where a shuttered assembly plan put 200 people out of work, Westport also hired some of the 325 workers displaced when the Upper Macungie building's previous occupant, J.C. Penney, closed its distribution center.

As Westport and Pratt become established in the Valley, Cunningham said the LVEDC is currently working to convince site selectors from three or four manufacturing companies to pick the Valley.

Cunningham said the Valley needs to show it has a skilled workforce to compete for manufacturing companies.

To ensure this, he said, the LVEDC is working with vocational technical schools, community colleges and the workforce investment board to meet employers' demand for nimble job certification programs.